Sealable bag having an integrated tray for use in vacuum packaging

ABSTRACT

A bag for use in vacuum packaging comprises a first panel and a second panel overlapping each other. One or more trays for retaining a perishable or other product is formed on one or more of the panels. Each tray can optionally have ridges for suspending a product above the tray so that liquid can collect in the tray. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.

PRIORITY CLAIM

This application claims priority to the following U.S. ProvisionalPatent Application:

U.S. Provisional Patent Application No. 60/452,172, entitled “SEALABLEBAG HAVING AN INTEGRATED TRAY FOR USE IN VACUUM PACKAGING,” by Henry Wu,et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01178US0).

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This U.S. patent application incorporates by reference all of thefollowing co-pending applications:

U.S. Provisional Patent Application No. 60/452,168, entitled“LIQUID-TRAPPING BAG FOR USE IN VACUUM PACKAGING,” by Henry Wu, et al.,filed Mar. 5, 2003 (Attorney Docket No. TILA-01177US0);

U.S. Provisional Patent Application No. 60/452,138, entitled “METHOD FORMANUFACTURING LIQUID-TRAPPING BAG FOR USE IN VACUUM PACKAGING,” by HenryWu, et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01177US1);

U.S. Provisional Patent Application No. 60/452,171, entitled “METHOD FORMANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED TRAY FOR USE IN VACUUMPACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No.TILA-01178US1);

U.S. Provisional Patent Application No. 60/451,954, entitled “SEALABLEBAG HAVING AN INDICIA FOR USE IN VACUUM PACKAGING,” by Henry Wu, et al.,filed Mar. 5, 2003 (Attorney Docket No. TILA-01179US0);

U.S. Provisional Patent Application No. 60/451,948, entitled “METHOD FORMANUFACTURING A SEALABLE BAG HAVING AN INDICIA FOR USE IN VACUUMPACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No.TILA-01179US1);

U.S. Provisional Patent Application No. 60/452,142, entitled “SEALABLEBAG HAVING AN INTEGRATED ZIPPER FOR USE IN VACUUM PACKAGING,” by HenryWu, et al., filed Mar. 5, 2003 (Attorney Docket No. TILA-01180US0);

U.S. Provisional Patent Application No. 60/452,021, entitled “METHOD FORMANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED ZIPPER FOR USE INVACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (AttorneyDocket No. TILA-01180US1);

U.S. Provisional Patent Application No. 60/451,955, entitled “SEALABLEBAG HAVING AN INTEGRATED VALVE STRUCTURE FOR USE IN VACUUM PACKAGING,”by Henry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No.TILA-01181US0);

U.S. Provisional Patent Application No. 60/451,956, entitled “METHOD FORMANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED VALVE STRUCTURE FORUSE IN VACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003(Attorney Docket No. TILA-01181US1);

U.S. Provisional Patent Application No. 60/452,157, entitled “SEALABLEBAG HAVING AN INTEGRATED TIMER/SENSOR FOR USE IN VACUUM PACKAGING,” byHenry Wu, et al., filed Mar. 5, 2003 (Attorney Docket No.TILA-01182US0);

U.S. Provisional Patent Application No. 60/452,139, entitled “METHOD FORMANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED TIMER/SENSOR FOR USEIN VACUUM PACKAGING,” by Henry Wu, et al., filed Mar. 5, 2003 (AttorneyDocket No. TILA-01182US1); and

U.S. patent application Ser. No. 10/169,485, entitled “METHOD FORPREPARING AIR CHANNEL EQUIPPED FILM FOR USE IN VACUUM PACKAGE,” filedJun. 26, 2002;

U.S. patent application Ser. No. ______, entitled “LIQUID-TRAPPING BAGFOR USE IN VACUUM PACKAGING,” Attorney Docket No. TILA-01177US2, filedconcurrently;

U.S. patent application Ser. No. ______, entitled “METHOD FORMANUFACTURING LIQUID-TRAPPING BAG FOR USE IN VACUUM PACKAGING,” AttorneyDocket No. TILA-01177US3, filed concurrently;

U.S. patent application Ser. No. ______, entitled “METHOD FORMANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED TRAY FOR USE IN VACUUMPACKAGING,” Attorney Docket No. TILA-01178US3, filed concurrently;

U.S. patent application Ser. No. ______, entitled “SEALABLE BAG HAVINGAN INDICIA FOR USE IN VACUUM PACKAGING,” Attorney Docket No.TILA-01179US2, filed concurrently;

U.S. patent application Ser. No. ______, entitled “METHOD FORMANUFACTURING A SEALABLE BAG HAVING AN INDICIA FOR USE IN VACUUMPACKAGING,” Attorney Docket No. TILA-01179US3, filed concurrently;

U.S. patent application Ser. No. ______, entitled “SEALABLE BAG HAVINGAN INTEGRATED ZIPPER FOR USE IN VACUUM PACKAGING,” Attorney Docket No.TILA-01180US2, filed concurrently;

U.S. patent application Ser. No. ______, entitled “METHOD FORMANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED ZIPPER FOR USE INVACUUM PACKAGING,” Attorney Docket No. TILA-01180US3, filedconcurrently;

U.S. patent application Ser. No. ______, entitled “SEALABLE BAG HAVINGAN INTEGRATED VALVE STRUCTURE FOR USE IN VACUUM PACKAGING,” AttorneyDocket No. TILA-01181US2, filed concurrently;

U.S. patent application Ser. No. ______, entitled “METHOD FORMANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED VALVE STRUCTURE FORUSE IN VACUUM PACKAGING,” Attorney Docket No. TILA-01181US3, filedconcurrently;

U.S. patent application Ser. No. ______, entitled “SEALABLE BAG HAVINGAN INTEGRATED TIMER/SENSOR FOR USE IN VACUUM PACKAGING,” Attorney DocketNo. TILA-01182US2, filed concurrently; and

U.S. patent application Ser. No. ______, entitled “METHOD FORMANUFACTURING A SEALABLE BAG HAVING AN INTEGRATED TIMER/SENSOR FOR USEIN VACUUM PACKAGING,” Attorney Docket No. TILA-01182US3, filedconcurrently.

FIELD OF THE INVENTION

The present invention relates to bags for use in vacuum packaging andmethods and devices for manufacturing bags for use in vacuum packaging.

BACKGROUND

Methods and devices for preserving perishable foods such as fish andmeats, processed foods, prepared meals, and left-overs, andnon-perishable items are widely known, and widely varied. Foods areperishable because organisms such as bacteria, fungus and mold grow overtime after a food container is opened and the food is left exposed tothe atmosphere. Most methods and devices preserve food by protectingfood from organism-filled air. A common method and device includesplacing food into a gas-impermeable plastic bag, evacuating the air fromthe bag using suction from a vacuum pump or other suction source, andtightly sealing the bag.

A bag for use in vacuum packaging can consist of a first panel andsecond panel, each panel consisting of a single layer of heat-sealable,plastic-based film (for example, polyethylene). The panels are sealedtogether along a substantial portion of the periphery of the panels byheat-sealing techniques so as to form an envelope. Perishable products,such as spoilable food, or other products are packed into the envelopevia the unsealed portion through which air is subsequently evacuated.After perishable products are packed into the bag and air is evacuatedfrom the inside of the bag, the unsealed portion is heated and pressedsuch that the panels adhere to each other, sealing the bag.

U.S. Pat. No. 2,778,173, incorporated herein by reference, discloses amethod for improving the evacuation of air from the bag by formingchannels in at least one of the panels with the aid of embossingtechniques. Air escapes from the bag along the channels duringevacuation. The embossing forms a pattern of protuberances on at leastone of the panels. The protuberances can be discrete pyramids,hemispheres, etc., and are formed by pressing a panel using heatedfemale and male dies. The first panel is overlaid on the second panelsuch that the protuberances from one panel face the opposite panel. Thecontacting peripheral edges of the panels are sealed to each other toform an envelope having an inlet at an unsealed portion of theperiphery. The perishable or other products are packed into the envelopethrough the inlet, and the inlet is sealed. Thereafter, an opening ispierced in apart of the panel material that communicates with thechannels, air is removed from the interior of the envelope through thechannels and opening, and the opening is sealed. This type of bagrequires two additional sealing steps after the perishable or otherproduct is packed into the envelope. One further problem is thatembossing creates impressions on the plastic such that indentations areformed on the opposite side of the panel

To avoid additional sealing steps, a vacuum bag is formed having a firstpanel and a second panel consisting of laminated films. Each panelcomprises a heat-sealable inner layer, a gas-impermeable outer layer,and optionally, one or more intermediate layers. Such a bag is describedin U.S. Pat. No. Re. 34,929, incorporated herein by reference. At leastone film from at least one panel is embossed using an embossing mold toform protuberances and channels defined by the space betweenprotuberances, so that air is readily evacuated from the vacuum bag.

U.S. Pat. No. 5,554,423, incorporated herein by reference, disclosesstill another bag usable in vacuum packaging. The bag consists of afirst and second panel, each panel consisting of a gas-impermeable outerlayer and a heat-sealable inner layer. A plurality of heat-sealablestrand elements are heat bonded at regular intervals to the inner layerof either the first panel or the second panel. The spaces between strandelements act as channels for the evacuation of air. The strand elementsare extruded from an extrusion head and heat bonded to the heat-sealablelayer by use of pressure rolls. Separate equipment is required forproducing strand elements, and a procedure of heat bonding a pluralityof strand elements at regular intervals to the heat-sealable inner layeris complicated. Also, various shapes of pattern are hard to form usingthis process.

BRIEF DESCRIPTION OF THE FIGURES

Further details of embodiments of the present invention are explainedwith the help of the attached drawings in which:

FIG. 1A is a perspective view of a method for manufacturing a vacuum bagin accordance with one embodiment of the present invention;

FIG. 1B is a side view of the method shown in FIG. 1A illustrating theembossing method used in an embodiment of the present invention;

FIG. 1C is a close-up view of a portion of FIG. 1B;

FIG. 2A is a plan view of a panel in accordance with one embodiment ofthe present invention, manufactured by the process shown in FIG. 1A-1C;

FIG. 2B is a cross-section view of a panel in accordance with oneembodiment of the present invention, manufactured by the process shownin FIG. 1A-1C; and

FIG. 3 is a perspective view of a vacuum bag in accordance with oneembodiment of the present invention.

DETAILED DESCRIPTION

FIGS. 1A-1C illustrate one embodiment of a method for manufacturing avacuum bag in accordance with the present invention. The vacuum bagcomprises a first panel and a second panel, wherein each panel comprisesa gas-impermeable base layer 108 and a heat-sealable inner layer 106with at least one panel having raised walls for preventing shifting ofperishable or other product contained inside the vacuum bag. Alaminating roll 102 and a cooling roll 104 are arranged so that theheat-sealable inner layer 106 can be laminated to the gas-impermeablebase layer 108 as the melt-extruded resin is cooled. As illustrated inFIG. 1C, the gap between the laminating roll 102 and the cooling roll104 can be controlled according to specifications (for example,thickness) of a panel for use in vacuum packaging. The temperature ofthe cooling roll 104 is maintained in a range such that themelt-extruded heat-sealable resin is sufficiently cooled to form thedesired pattern. For example, a temperature range of about −15° C. toabout −10° C. can be sufficient to properly form the desired pattern.The temperature range of the cooling roll 104 can vary according to thecomposition of the resin, the composition of the gas-impermeable baselayer 108, environmental conditions, etc. and can require calibration.Also, the cooling roll 104 can be sized to have a larger diameter thanthe laminating roll 102, thereby bringing the melt-extruded resin intocontact with more cooled surface area. For example, the diameter of thecooling roll 104 can be about one-and-a-half to about three times aslarge as that of the laminating roll 102.

The heat-sealable inner layer 106 is typically made of a thermoplasticresin. For example, the resin can be comprised of polyethylene (PE)suitable for preserving foods and harmless to a human body. A vacuum bagcan be manufactured by overlapping two panels such that theheat-sealable resin layers 106 of the two panels is brought into contactand heat is applied to a portion of the periphery of the panels to forman envelope. The thermoplastic resin can be chosen so that the twopanels strongly bond to each other when sufficient heat is applied.

The gas-impermeable base layer 108 is fed to the gap between the coolingroll 104 and the laminating roll 102 by a feeding means (not shown). Thegas-impermeable base layer can be comprised of polyester, polyamide,ethylene vinyl alcohol (EVOH), nylon, or other material having similarproperties and capable of being used in this manufacturing process, andalso capable of being heated. The gas-impermeable base layer 108 canconsist of one layer, or two or more layers. When employing amultilayer-structured base layer, it should be understood that a totalthickness thereof is also adjusted within the allowable range for thetotal gas-impermeable base layer 108.

An extruder 110 is positioned in such away that the melt-extruded resinis layered on the gas-impermeable base layer 108 by feeding themelt-extruded resin to the nip between the cooling roll 104 and thegas-impermeable layer 108. The resin is fed through a nozzle 112 of theextruder 110. The temperature of the melt-extruded resin is dependent onthe type of resin used, and can typically range from about 200° C. toabout 250° C. The amount of resin to be extruded into the laminatingunit 100 is dependent on the desired thickness of the heat-sealableinner layer 106.

A pattern fabricated on the circumferential surface of the cooling roll104 in accordance with one embodiment of the present invention caninclude cavities for forming raised walls defining one or more discretetrays. The pattern can also optionally include cavities (and/orprotuberances) for forming ridges or protuberances within the raisedwalls for suspending a perishable or other product over a base of thetrays, thereby allowing liquid to collect in the tray. The resinextruded by the nozzle 112 is pressed between the cooling roll 104 andthe gas-impermeable base layer 108 and flows into the cavities of thecooling roll 104. The melt-extruded resin quickly cools and solidifiesin the desired pattern while adhering to the gas-impermeable base layer108, thereby forming the heat sealable inner layer 106 of the panel. Theheat-sealable inner layer 106 can be formed while the resin issufficiently heated to allow the resin to flow, thereby molding theresin, unlike conventional methods adopting a post-embossing treatmentwhere the heat-sealable inner layer is drawn by a die or embossedbetween male and female components.

FIG. 2A is a plan view of a panel formed by the cooling roll 104 for usein a vacuum bag, in which the heat-sealable inner layer 106 is molded insuch a way that raised walls 232 are formed for defining a tray 230 forrestricting the movement of perishable or other products. Within theraised walls 232 of the tray are ridges 234 for suspending theperishable or other products over the base of the tray. As shown, theridges 234 are cross-hatched and form reservoirs 236 for liquid tocollect. In other embodiments, the ridges can be formed in a multitudeof different patterns, allowing for the formation of reservoirs 236having a multitude of different shapes and sizes. In still otherembodiments, the tray 230 can include protuberances, wherein theprotuberances can be discrete pyramids, hemispheres, etc., therebyallowing liquid to collect evenly in the base of the tray 230. In stillother embodiments, the panel 220 can include a plurality of discretetrays 230, each sized to suit an application and optionally havingridges 234 or protuberances. One of ordinary skill in the art canappreciate the myriad of different ways in which the panel 220 can beconfigured to restrict the movement of perishable products within avacuum bag.

The thickness of the raised walls 232 and ridges 234 formed on theheat-sealable inner layer 106 of a panel 220 can be determined by thedepth of the cavities of the cooling roll 104, and the width of theraised walls 232 and ridges 234 can be determined by the width of thecavities. Thus, the shape, width, and thickness of the raised walls 232and ridges 234 can be controlled by changing the specifications for thecavities of the cooling roll 104. FIG. 2B is a cross-sectional view ofthe panel 220 described above. In the heat-sealable inner layer 106, theraised walls 232 can range, for example, from about 35-75 mils or morein height, the gas-impermeable base layer 108 can range, for example,from about 0.5-8.0 mils in thickness, and the heat-sealable inner layer106, can range, for example, from about 0.5-6.0 mils in thickness(without the raised walls 232). Optionally, ridges 234 or protuberancescan by included. The ridges 234 or protuberances can have a height lowerthan the raised walls 232, thereby suspending the perishable or otherproduct while still retaining the perishable product within the tray230. For example, if the raised wall 232 is 75 mils in height, theheight of the ridges 234 or protuberances can be about 30 mils. Thedimensions of the raised walls 232, the ridges 234, the base layer 108,and the inner layer 106 are set forth to illustrate, but are not to beconstrued to limit the dimensions.

FIG. 3 illustrates a bag for use in vacuum packaging in accordance withone embodiment of the present invention. The vacuum bag 350 comprises afirst panel 320 and a second panel 322 overlapping each other. At leastone tray 230 is formed on the first panel 320 in accordance with anembodiment described above. The second panel 322 (or first panel 320)optionally includes channels (not shown) along a portion of the panelfor evacuating air and other gases from the bag. The channels can beformed, for example, as described in the cross-referenced application“LIQUID-TRAPPING BAG FOR VACUUM PACKAGING,” incorporated herein byreference. The heat-sealable resin layer 106 and the gas-impermeablebase layer 108 of the first and second panels 320,322 are typically madeof the same material respectively, but can alternatively be made ofdifferent materials that exhibit heat-sealability and gas-impermeabilityrespectively. As described above, the heat-sealable resin layer 106 isused as an inner layer and the gas-impermeable base layer 108 is used asan outer layer. The lower, left, and right edges of the first and thesecond panel 320,322 are bonded to each other by heating, so as to forman envelope for receiving a perishable or other product to be vacuumpackaged. Once a perishable or other product is placed in the vacuum bag350, air and/or other gases can be evacuated from the bag 350, forexample by a vacuum sealing machine as described in U.S. Pat. No.4,941,310, which is incorporated herein by reference. Once the airand/or other gases are evacuated to the satisfaction of the user, theinlet can be sealed by applying heat, thereby activating theheat-sealable inner layers 106 and bonding them together.

The foregoing description of preferred embodiments of the presentinvention has been provided for the purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Obviously, many modificationsand variations will be apparent to the practitioner skilled in the art.The embodiments were chosen and described in order to best explain theprinciples of the invention and its practical application, therebyenabling others skilled in the art to understand the invention forvarious embodiments and with various modifications that are suited tothe particular use contemplated. It is intended that the scope of theinvention be defined by the following claims and their equivalence.

1. A bag adapted to receive an article, comprising: a first paneldefining a tray adapted to receive the article and a plurality ofprotuberances within the tray, which protuberances are adapted tosupport the article over a base of the tray; a second panel; and thefirst panel and the second panel secured together to form the bag. 2.The bag of claim 1 wherein said first panel is formed of a heat sealablematerial and said second panel is formed of a gas impermeable material.3. A bag adapted to receive an article, comprising: a first panelhaving: a first outer layer; and a first inner layer connected with thefirst outer layer, the first inner layer including at least one trayintegrally formed with the first inner layer; a second panel connectedwith the first panel such that the first panel and the second panel forman envelope having an inlet, the second panel having: a second outerlayer; and a second inner layer connected with the second outer layer.4. The bag of claim 3, further comprising a plurality of protuberanceswithin the at least one trays.
 5. The bag of claim 3, wherein the firstouter layer and the second outer layer comprise a gas-impermeablematerial.
 6. The bag of claim 5, wherein the gas-impermeable material isone of polyester, polyamide, ethylene vinyl alcohol, and nylon.
 7. Thebag of claim 3, wherein the first inner layer and the second inner layercomprise a thermoplastic resin.
 8. The bag of claim 7, wherein thethermoplastic resin is polyethylene.
 9. The bag of claim 5, wherein whenthe article is positioned within the tray, the article is supported bythe plurality of protuberances.
 10. The bag of claim 4, wherein when thearticle is positioned within the tray, the article is supported above abase of the at least one tray.
 11. The bag of claim 4, wherein theplurality of protuberances define a plurality of pockets formed suchthat liquid can collect in the plurality of pockets; and wherein whenthe article is positioned within the tray, the article is positionedabove liquid collected in the plurality of pockets.
 12. A bag adapted toreceive an article, comprising: a first panel including: a firstgas-impermeable layer; and a first inner layer laminated to the firstgas-impermeable layer, the first inner layer including at least one trayintegrally formed with the first inner layer; a second panel including:a second gas-impermeable layer; and a second inner layer laminated tothe second gas-impermeable layer; and wherein the first panel isconnected with the second panel to form an envelope such that the firstinner layer opposes the second inner layer, the envelope including aheat-sealable opening for evacuating gas.
 13. The bag of claim 12,further comprising a plurality of protuberances within the at least onetrays.
 14. The bag of claim 12, wherein the first gas-impermeable layerand the second gas-impermeable layer comprise one of polyester,polyamide, ethylene vinyl alcohol, and nylon.
 15. The bag of claim 12,wherein the first inner layer and the second inner layer comprise athermoplastic resin.
 16. The bag of claim 15, wherein the thermoplasticresin is polyethylene.
 17. The bag of claim 13, wherein when the articleis positioned within the tray, the article is supported by the pluralityof protuberances.
 18. The bag of claim 13, wherein when the article ispositioned within the tray, the article is supported above a base of theat least one tray.
 19. The bag of claim 13, wherein the plurality ofprotuberances define a plurality of pockets formed such that liquid cancollect in the plurality of pockets; and wherein when the article ispositioned within the tray, the article is positioned above liquidcollected in the plurality of pockets.
 20. A heat-sealable bag adaptedto receive an article, comprising: a first panel including: a firstgas-impermeable layer; at least one first intermediate layer connectedwith the first gas-impermeable layer; and a first inner layer laminatedto the at least one first intermediate layer, the first inner layerincluding at least one tray integrally formed with the first innerlayer; and a second panel including: a second gas-impermeable layer; atleast one second intermediate layer connected with the secondgas-impermeable layer; and a second inner layer laminated to the atleast one second intermediate layer; wherein the first panel isconnected with the second panel to form an envelope such that the firstinner layer opposes the second inner layer, the envelope including aheat-sealable opening for evacuating gas.
 21. The bag of claim 20,further comprising a plurality of protuberances within the at least onetrays.
 22. The bag of claim 20, wherein the first gas-impermeable layerand the second gas-impermeable layer comprise one of polyester,polyamide, ethylene vinyl alcohol, and nylon.
 23. The bag of claim 20,wherein the first inner layer and the second inner layer comprise athermoplastic resin.
 24. The bag of claim 23, wherein the thermoplasticresin is polyethylene.
 25. The bag of claim 21, wherein when the articleis positioned within the tray, the article is supported by the pluralityof protuberances.
 26. The bag of claim 21, wherein when the article ispositioned within the tray, the article is supported above a base of theat least one tray.
 27. The bag of claim 21, wherein the plurality ofprotuberances define a plurality of pockets formed such that liquid cancollect in the plurality of pockets; and wherein when the article ispositioned within the tray, the article is positioned above liquidcollected in the plurality of pockets.